I am using SparkFun device and the Actuator/Sensor would be MLX90640. I have installed the MLX90640 GitHub repos and trying to implement one of the given code sample and I have edited my c_cpp_properties.json file to add the files but I am unable to resolve the issue for isConnected().#include “MLX90640_API.h”#include “MLX90640_I2C_Driver.h”

It’s declared at the bottom of the .ino file. You’re attempting to compile a .ino file as a cpp file, but you have to do some conversion first. In C++, the prototypes of all functions must be known at the time they’re called, and the call to isConencted violates that. (Arduino auto-generates these protyptes for you). See the FAQ.

It’s implemented in MLX90640_API.cpp. You have the wrong firmware structure (but the library is pretty weirdly structured, too…). Basically PIO is not compiling in MLX90640_API.cpp and MLX90640_I2C.cpp etc because it’s in a folder named “Example…”. Usually these sources would be have to be under src/ with the examples being in folders under example/.

Can you try and copy the all the four MLX... files from the Example1 folder to your src/ where main.cpp is? Nothing else.